SGER: Service Paths -- Optimizing end-to-end Behaviors in Distributed Service Architectures

分布式应用程序及其运行的硬件/软件平台正变得越来越复杂。因此，理解和管理应用程序行为也变得越来越困难，特别是对于那些对组织提供其有合同义务的服务的能力至关重要的应用程序。佐治亚理工学院的“服务路径”项目正在开发以下技术：(1)通过分布式服务集动态发现应用程序遵循的关键“路径”，以及(2)管理这些路径，以提高应用程序满足动态服务级别协议的能力。服务路径技术将大大提高系统提供端到端保证的能力，并增强底层系统提供这种保证的能力。具体成果包括：新的系统级方法和抽象以更好地了解当前的应用程序行为，新的中间件抽象适用于跨多个机器构建和管理大规模软件覆盖，以及使用PlanetLab等虚拟化平台和新的硬件支持运行时平台虚拟化所取得的实验结果。更广泛的意义：开发和更改现代IT基础设施的成本现在由人员主导，而不是硬件。技术提供商对这一事实的反应是，开发复杂的分布式应用程序变得越来越容易。如果不了解并随后能够管理和控制这些应用程序，在开发时获得的成本节约不能转化为使美国行业与低成本国际供应商竞争所需的持续成本节约。

Distributed applications and the hardware/software platforms on which theyrun are becoming increasingly complex. As a result, it is also becomingincreasingly difficult to understand and then manage application behavior,particularly for applications that are critical to the ability oforganizations to provide services for which they have contractual obligations.Georgia Tech's `Service Paths' project is developing technologies for(1) dynamically discovering the critical `paths' applications followthrough distributed sets of services, and (2) managing such paths inorder to improve an application's ability to meet dynamic service levelagreements. Service path technologies will substantially improve systems'abilities to provide end-to-end guarantees and enhance the underlyingsystems' capabilities to provide such guarantees. Concrete outcomes includenew system-level methods and abstractions to better understand currentapplication behavior, new middleware abstractions suitable both forconstructing and managing large-scale software overlays across manymachines, and experimental results attained with virtualized platformslike PlanetLab and with novel hardware support for runtime platformvirtualization.Broader significance: the costs of developing and changing modern ITinfrastructures are now dominated by personnel rather than hardware.Technology providers have reacted to this fact by making it increasinglyeasy to develop complex distributed applications. Without alsounderstanding and then being able to manage and control such applications,cost savings attained at development time cannot be translated to thecontinuing cost savings required to make U.S. industry competitive withlow-cost, international providers.